Oral administration of Bis(aspirinato)zinc(II) complex ameliorates hyperglycemia and metabolic syndrome-like disorders in spontaneously diabetic KK-A(y) mice: structure-activity relationship on zinc-salicylate complexes

In recent years, the number of patients suffering from diseases, such as cancer, apoplexy, osteoporosis, hypertension, and type 2 diabetes mellitus is increasing worldwide. Type 2 diabetes, a lifestyle-related disease, is recognized as a serious disease. Various types of pharmaceutics for diabetes have been used. Since the relationship between diabetes and biometals such as vanadium, copper, and zinc ions has been recognized for many years, we have been developing the anti-diabetic metal complexes as new candidates. We found that several zinc(II) (Zn) complexes exhibit glucose-lowering activity for treating type 2 diabetes. High doses of salicylates have been known to reverse hyperglycemia and hyperinsulinemia in type 2 diabetic patients. These findings strongly suggest that the combined use of Zn and salicylates achieves the synergism in treating type 2 diabetes. Because aspirin, acetyl salicylic acid, has a chelating ability, we used it as a ligand to Zn. Several Zn-salicylate complexes were prepared and their biological activities were examined in this study. The complexes with an electron-withdrawing group in the ligand exhibited higher in vitro insulinomimetic activity than those of Zn complexes with an electron-donating group in the ligand. When bis(aspirinato)Zn (Zn(asp)?) complex was orally administered on KK-A(y) mice with hereditary type 2 diabetes, the diabetic state was improved. In addition, this complex exhibited normalizing effects on serum adiponectin level and high blood pressure in metabolic syndrome. In conclusion, Zn(asp)? complex is newly proposed as a potent anti-diabetic and anti-metabolic syndrome agent.     

Highly Stable Duplex Formation by Artificial Nucleic Acids Acyclic Threoninol Nucleic Acid (aTNA) and Serinol Nucleic Acid (SNA) with Acyclic Scaffolds

The stabilities of duplexes formed by strands of novel artificial nucleic acids composed of acyclic threoninol nucleic acid (aTNA) and serinol nucleic acid (SNA) building blocks were compared with duplexes formed by the acyclic glycol nucleic acid (GNA), peptide nucleic acid (PNA), and native DNA and RNA. All acyclic nucleic acid homoduplexes examined in this study had significantly higher thermal stability than DNA and RNA duplexes. Melting temperatures of homoduplexes were in the order of aTNA>PNA≈GNA≥SNA?RNA>DNA. Thermodynamic analyses revealed that high stabilities of duplexes formed by aTNA and SNA were due to large enthalpy changes upon formation of duplexes compared with DNA and RNA duplexes. The higher stability of the aTNA homoduplex than the SNA duplex was attributed to the less flexible backbone due to the methyl group of D ‐threoninol on aTNA, which induced clockwise winding. Unlike aTNA, the more flexible SNA was able to cross‐hybridize with RNA and DNA. Similarly, the SNA/PNA heteroduplex was more stable than the aTNA/PNA duplex. A 15‐mer SNA/RNA was more stable than an RNA/DNA duplex of the same sequence.     

Vinyl Polymerization Initiated by Cycloheptaamylose Phosphate Ammonium Salt/Metal Ion System in Water

Cycloheptaamylose phosphate ammonium salt (β-PCD) was found to initiate the radical polymerization of vinyl monomers in combination with water and a small amount of Cu(n) or Fe(III) ion, in analogy with the cycloheptaamylose (β-cyclodextrin:β-CD). The initiating ability of this system was larger than that of the β-CD/metal ion system. Detailed investigations were conducted in order to elucidate a plausible initiation mechanism of this polymerization.     

Release potential of single-wall carbon nanotubes produced by super-growth method during manufacturing and handling

We investigated the release potential of single-wall carbon nanotubes (CNTs) produced by the super-growth method during their manufacturing and handling processes at a research facility. We generally sampled air at points both outside and inside of protective enclosures such as a glove box and fume hood. Sampling the air outside of the enclosures was intended to evaluate the actual exposure of workers to CNTs, while sampling the air inside the enclosures was performed to quantify the release of CNTs to the air in order to estimate the potential exposure of workers without protection. The results revealed that airborne CNTs were generated when (1) CNTs were separated from the substrates using a spatula and placed in a container in a glove box; (2) an air gun was used to clean the air filters (containing dust that included CNTs) of a vacuum cleaner; (3) a vacuum cleaner was used to collect CNTs (emission with exhaust air from the cleaner); (4) the container of CNTs was opened; and (5) CNTs in the bin of the cleaner were transferred to a container. In these processes, airborne CNTs were only found inside the enclosures, except for a small amount of CNTs released from the glove box when it was opened. Electron microscopic observations of aerosol particles found CNT clusters, which were fragments of CNT forests, with sizes ranging from submicrometers to tens of micrometers.     

Optical orthogonal frequency division multiplexing demultiplexer using slab star coupler-based optical discrete Fourier transform circuit

We demonstrate an optical orthogonal frequency division multiplexing (OFDM) demultiplexer with an optical discrete Fourier transform circuit fabricated using silica planar lightwave circuit technology. This compact device can process an arbitrary number of subcarriers. The operation of a ten-channel device is demonstrated by demultiplexing a 100 Gbit/s (10 subcarrier × 10 Gbits/s) OFDM signal. We also discuss a main factor affecting characteristics degradation of the device.     

Efficient Light‐Harvesting Antennae Resulting from the Dense Organization of Dyes into DNA Junctions through d‐Threoninol

Herein we report the construction of efficient light‐harvesting antennae by hybridization of DNA oligonucleotides containing high densities of fluorophores into DNA junctions through d ‐threoninol. Six pyrene donors could be incorporated into each arm without self‐quenching. A perylene acceptor was located at the center of the junction. Antenna effects of a duplex and three‐ to eight‐way junctions were systematically compared. Six‐ and eight‐way junctions had the highest antenna effects, and their effective absorption coefficients were 8.5 times higher than that of perylene. Interestingly, even‐numbered junctions had higher efficiencies than odd‐numbered junctions. Nondenaturing gel analyses and fluorescence lifetime measurements demonstrated that the strong odd–even effects were derived from differences in the stability of junctions. The results presented will guide the design of efficient artificial photosynthetic systems.     

C1 Oxidation/C2 Reduction Isomerization of Unprotected Aldoses Induced by Light/Ketone

Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water‐soluble benzophenone. Whereas its anomeric carbon (C1) is oxidized to a carboxy group, the hydroxy group on the C2 carbon is replaced by hydrogen. The generated 2‐deoxy lactones are readily reduced to the corresponding 2‐deoxy aldoses, which are often contained in bioactive compounds.     

Multilayer lattice gas model in the quasichemical approximation

The multilayer lattice gas model is dealt with in the quasichemical approximation. A restriction on the atomic stacking is also introduced in the system so that an atom can occupy only a lattice site whose underlying nearest neighbor lattice sites are all occupied by atoms. The critical condensation of atoms is investigated as the substrate potential is varied. The theory is also applied to the surface roughening of the crystalline bulk.     

Specular reflection of helium and hydrogen molecular beams from the (111) plane of silver

The Debye—Waller (DW) factor in the specular reflection intensity of He and H₂ molecular beams from the Ag (111) plane has been studied experimentally and theoretically. A new expression for the DW factor corrected for a stationary part of the gas—surface interaction potential is derived kinematically and semi-classically by the use of a Morse potential. An analysis of the experimental data through the above DW factor yields a surface Debye temperature of 251 ± 20 K, which is unusually high, and potential depths of 1.5 ± 1.0 meV for He and 6.4 ± 2.9 meV for H₂, which seem slightly too small. These results are discussed on the basis of the nature of gas-surface interactions and in comparison with the results deduced from the conventional DW factor corrected for a constant attractive potential depth.     

Chain orientation and intrinsic anisotropy in birefringence-free polymer blends

We found 10 miscible pairs of dissimilar polymers that rendered birefringence-free polymer blends. Each pair consists of a positive birefringence polymer and a negative one. Zero birefringence in the blend is attained as the result of compensation of positive and negative contributions to the overall birefringence. This concept was confirmed by characterizing the chain orientation of individual chains in the blend using polarized Fourier-transform infrared spectroscopy and by estimating theoretically the intrinsic optical anisotropy of the chain molecules.